So I have 2 Blue Smart chargers, a 12/15 and a 12/5. I normally use them on my motorhome with no issues. Today I load tested 2 Motorcraft FLA starting batteries and afterwards went to charge them back up. (One of the Motorcrafts is 2.5 years old and the other is 5 years old). I started with the older battery and put it on the 12/15. After a few hours on absorption it was getting close to float as current was low so I pulled it off and put the 12/15 on the other, newer battery and put the 12/5 on the older battery to finish it off. A short time later I checked on things and noticed the 12/5 was clicking on and off about every 10 seconds. Current was low, under .4 amp, and I thought maybe it was getting ready to switch to float, and eventually it did go to float but the clicking on and off continued even in float. After about 1/2 hour of this I got the idea to swap the chargers around and I put the 12/5 on the newer battery and the 12/15 on the older one. They both went into absorption after a few seconds and I watched them for a while and this time the 12/5 stayed on with no clicking. Current was low again on both, under .5 amps. After 30 min they both went to float, and again no cycling on and off. The only difference is the age of the batteries, and they both check out OK on a load test and A SOC voltage test before the load tests showed 12.7 volts on each one. The 12/5 only cycles on and off on the older battery and the 12/15 doesn't cycle on and off on either one. It can't be an overload because the current is very low when this happens.
A search turned up this issue with others and it was always the 12/5 chargers, and none were ever resolved. No one from Victron stepped in on any of the others either. Any ideas here?
